World's barriers: Ceuta and Melilla

Many migrants still try to use the Spanish enclaves as the route to escape poverty in Africa

On the 20th anniversary of the fall of the Berlin Wall, BBC Mundo looks at barriers which are still standing - or have gone up since - around the world.

At the end of the 20th Century, Spain decided to build two barriers in Ceuta and Melilla, to prevent enormous illegal immigration from Africa.

WALLS STILL STANDING West Bank Northern Ireland Saudi Arabia Melilla and Ceuta Cyprus Pakistan-Iran Rio de Janiero Mexico-US India-Pakistan Korean border Western Sahara Iraq-Kuwait Botswana-Zimbabwe

These two autonomous cities, situated on the other side of the straits of Gibraltar in the midst of African territory, represent the easiest access into Europe from Africa.

Erected in the 1990s, the 8.2km (5 miles) of wire fences in Ceuta and 12km in Melilla, have since been modernised.

The surge of illegal immigration into Spain recorded at the start of 2000 led Spanish and European authorities to reinforce security, constructing three parallel fences in each city.

The height of each wall was increased to 6m (19ft), infrared cameras were installed, as well as tear gas canisters, noise and movement sensors and control towers.

A maze of interlocking cables and spikes await anyone who manages to scale the moving ladder-resistant summit of the first fences.

However successful the Spanish authorities have been in controlling immigration, the people of Ceuta and Melilla have had to pay a price, living as they do in a fortified city.